Plimer questions Monbiot
These are Ian Plimer's 13 problems for George Monbiot, With analysis from various sources, especially Real Climate and Chris Colose's Climate Change interspersed among the problems/questions: Explain the Medieval Warming Period I The romans grew grapes in the UK, so it must have been warm then. -- Andrew Dodds, summarizing Plimer at Open Mind Monbiot vs Plimer « Open Mind From the distribution of the vines, olives, citrus and grain crops in Europe, UK and Greenland, calculate the temperature in the Roman and Medieval Warmings and the required atmospheric CO2 content at sea level to drive such warmings. What are the errors in your calculation? Reconcile your calculations with at least five atmospheric CO2 proxies. Show all calculations and justify all assumptions. It is rather strange why Plimer requests agriculture as a proxy for paleotemperature (and what?s stranger is what this has to do with anything). The answer about the error is simply that it will be ?large? and will not be indicative of global temperatures, even if temperature is the dominant climatic variable picked up by changes in vines and crops. What?s more interesting is the statements about Carbon Dioxide. Plimer plays an interesting trick here and assumes that these climate changes were in fact caused by Carbon Dioxide (which they weren?t). The question about CO2 content at sea level is a hypothetical question (how much CO2 would it take to cause the climate change?), but then he asks Monbiot to reconcile this with observations (I?m not sure why he needs five, I?d just use ice core records here as a starting choice.) But what if CO2 didn?t cause those warmings? In that case, Monbiot could answer the hypothetical first question, but there would be nothing to answer for the second part of the question since the justification itself would be expected to be void. It?s like if someone asked me how much the globe would cool if we removed all the CO2 from the atmosphere (which is an interesting question) but then asking me to back that up with proxy data, as if this actually happened before. Even to answer the first question about ?CO2 content? would include some caveats since it?s the *change* in CO2 that matters for driving warming, not the absolute content, and it?s the fractional increase (not the absolute increase) that matters and so you?d need to know the baseline value of CO2. This is not difficult to get from proxies (and not much different from pre-industrial values) but the question as stated makes little sense. Furthermore, CO2 is well-mixed in the atmosphere and so there?s no reason to confine the question to sea-level, especially since CO2 in the upper atmosphere matters significantly for radiative transfer.-- Chris Colose, Climate Change Ian Plimer's questions to George Monbiot The natural proxies including species distribution and farming conditions we have now have been observed with more precision than anything going on in the Medieval Warm Period, so the error for that period from natural proxies has to be far higher than for similar proxies now -- Marion Delgado, commenting at Climate Change Rule out volcanos I All the CO2 comes from Volcanoes.-- Andrew Dodds Tabulate the CO2 exhalation rates over the last 15,000 years from (i) terrestrial and submarine volcanism (including maars, gas vents, geysers and springs) and calc-silicate mineral formation, and (ii) CH4 oxidation to CO2 derived from CH4 exhalation by terrestrial and submarine volcanism, natural hydrocarbon leakage from sediments and sedimentary rocks, methane hydrates, soils, microbiological decay of plant material, arthropods, ruminants and terrestrial methanogenic bacteria to a depth of 4 km. From these data, what is the C12, C13 and C14 content of atmospheric CO2 each thousand years over the last 15,000 years and what are the resultant atmospheric CO2 residence times? All assumptions need to be documented and justified. The whole point here is to sound smart. There?s nothing here remotely relevant to what Monbiot wanted to debate. One can certainly pull up tree ring or ice core data to get C13/C12 ratios as a time-series, or (probably more relevant) CO2 concentration in the atmosphere whose fluctuations will tell you something useful about net emission/uptake and whether the carbon cycle has been perturbed, as well as residency time. We don?t know emissions from every individual source and there?s also not much point in throwing the ?From these data?? connection since certain proxies record CO2 content in the atmosphere to pretty high accuracy without knowing where it came from. -- Chris Colose Rule out clouds I There is uncertainty over the effects of clouds, therefore there is no CO2-greenhouse effect. -- Andrew Dodds From first principles, calculate the effects on atmospheric temperature at sea level by changes in cloudiness of 0.5%, 1% and 2% at 0%, 20%, 40%, 60% and 80% humidity. What changes in cloudiness would have been necessary to drive the Roman Warming, Dark Ages, Medieval Warming and Little Ice Age? Show all calculations and justify all assumptions. Changes in cloudiness at 0% humidity indeed!! Obviously some of these situations are unphysical and so preclude any realistic calculation and cloud change is generally thought to be a feedback. It also depends not only on cloud amount but distribution of cloud type, as changing high clouds and low clouds (or for example one could decrease the area coverage but increase the cloud top altitude) would have different, even competing effects. One crude estimate presented by Dennis Hartmann is his book ?Global Physical Climatology? is that the fractional area of cloud cover is about 50% and has a net -20 W/m2 impact on the energy balance, and thus the partial derivative of the net radiative energy input at the TOA with respect to the total fractional area of clouds would imply that a 10% change in cloud fraction would either offset or double the RF for a doubling of carbon dioxide.-- Chris Colose, Climate Change Um. I don't think "The Dark Ages" is a climate epoch, and I don't think the term is really in vogue anymore amongst historians. Unless Plimer is suggesting that the Dark Ages were dark because it was extremely cloudy. MarkG commenting at Deltoid Plimer fails to answer Monbiot Rule out Volcanos II All the CO2 comes from Volcanoes.Truly bizarre attack on the isotope evidence proving otherwise -- Andrew Dodds Calculate the changes in atmospheric C12 and C13 content of CO2 and CH4 from crack-seal deformation. What is the influence of this source of gases on atmospheric CO2 residence time since 1850? Validate assumptions and show all calculations. Get around CO2 follows T I - Explain Faint Sun Paradox There was more CO2 in the air in previous ice ages the sun was fainter, therefore CO2 does not drive temperature. -- Andrew Dodds From CO2 proxies, carbonate rock and mineral volumes and stable isotopes, calculate the CO2 forcing of temperature in the Huronian, Neoproterozoic, Ordovician, Permo-Carboniferous and Jurassic ice ages. Why is the "faint Sun paradox" inapplicable to the Phanerozoic ice ages in the light of your calculations? All assumptions must be validated and calculations and sources of information must be shown. Get around CO2 follows T II The increase in CO2 comes from the oceans heating, not the other way around. -- Andrew Dodds From ocean current velocity, palaeotemperature and atmosphere measurements of ice cores and stable and radiogenic isotopes of seawater, atmospheric CO2 and fluid inclusions in ice and using atmospheric CO2 residence times of 4, 12, 50 and 400 years, numerically demonstrate that the modern increase in atmospheric CO2 could not derive from the Medieval Warming. Bascially in an overcomplicated way, Plimer is asking to show that the modern rise in CO2 is not a feedback from medieval warming. This is probably some offshoot of the whole ?CO2 lags temperature? line. One issue here is that the perturbation lifetime of CO2 is different than the ?lag time? which occurs as a response to warming. Even then no one expects an abrupt decadal scale rise of CO2 centuries after the event, which isn?t even what occurred in the glacial-interglacial cycles, which were considerably larger in magnitude and spatial extent then the MWP. The rate of change is today of CO2 is orders of magnitude larger, and the absolute concentration is also much higher than the whole ice core record show and even much longer. We also know that today?s CO2 increase is anthropogenic because CO2 is going into the ocean (ocean acidification, duh) not going out and isotopic signatures of light and heavy carbon changes. -- Chris Colose, Climate Change Yes, Plimer is really arguing that recent CO2 increases were caused by Medieval Warming. Isotopes measurements show that this increase mainly came from burning fossil fuels, but my link goes to RealClimate so Plimer will dismiss it with one of his usual ad hominem attacks. -- Tim Lambert, Deltoid Rule out space dust There is some uncertainty over aerosols, therefore there is no CO2-greenhouse effect. -- Andrew Dodds Calculate the changes in the atmospheric transmissivity of radiant energy over the last 2,000 years derived from a variable ingress of stellar, meteoritic and cometary dust, terrestrial dust, terrestrial volcanic aerosols and industrial aerosols. How can your calculations show whether atmospheric temperature changes are related to aerosols? All assumptions must be justified and calculations and sources of information must be shown. Use geology jargon to prove you understand climate I?m pretty sure that MORB circulation systems don?t metamorphose rocks to GS facies, the pressures are far too low; Pilmer has his geology wrong in this meaningless question. -- Andrew Dodds Calculate 10 Ma time flitches using W/R ratios of 10, 100 and 500 for the heat addition to the oceans, oceanic pH changes and CO2 additions to bottom waters by alteration of sea floor rocks to greenschist and amphibolite facies assemblages, the cooling of new submarine volcanic rocks (including MORBs) and the heat, CO2 and CH4 additions from springs and gas vents since the opening of the Atlantic Ocean. From your calculations, relate the heat balance to global climate over these 10 Ma flitches. What are the errors in your calculations? Show all calculations and discuss the validity of any assumptions made. Prove sea level rise is not due to retreating glaciers I think he is trying to claim that sea level rise is due to the last deglaciation. -- Andrew Dodds Calculate the rate of isostatic sinking of the Pacific Ocean floor resulting from post LGM loading by water, the rate of compensatory land level rise, the rate of gravitationally-induced sea level rise and sea level changes from morphological changes to the ocean floor. Numerically reconcile your answer with the post LGM sea level rise, oceanic thermal expansion and coral atoll drilling in the South Pacific Ocean. What are the relative proportions of sea level change derived from your calculations? Get around CO2 follows T III The increase in CO2 comes from the oceans heating, not the other way around. -- Andrew Dodds From atmospheric CO2 measurements, stable isotopes, radiogenic Kr and hemispheric transport of volcanic aerosols, calculate the rate of mixing of CO2 between the hemispheres of planet Earth and reconcile this mixing with CO2 solubility, CO2 chemical kinetic data, CO2 stable and cosmogenic isotopes, the natural sequestration rates of CO2 from the atmosphere into plankton, oceans, carbonate sediments and cements, hydrothermal alteration, soils, bacteria and plants for each continent and ocean. All assumptions must be justified and calculations and sources of information must be shown. Calculations may need to be corrected for differences in 12CO2, 13CO2 and 14CO2 kinetic adsorption and/or molecular variations in oceanic dissolution rates. Give a short course in historical climate modeling Models are all unreliable and wrong. And if you don?t know absolutely everything about climate change, then you don?t know anything. -- Andrew Dodds Calculate from first principles the variability of climate, the warming and cooling rates and global sea level changes from the B�lling to the present and compare and contrast the variability, maximum warming and maximum sea level change rates over this time period to that from 1850 to the present. Using your calculations, how can natural and human-induced changes be differentiated? All assumptions must be justified and calculations and sources of information must be shown. Rule out aerosols II Is really a rehash of ?If CO2 is responsible for climate change now, it must ALWAYS be responsible for EVERY climate change?. -- Andrew Dodds Calculate the volume of particulate and sulphurous aerosols and CO2 and CH4 coeval with the last three major mass extinctions of life. Use the figures derived from these calculations to numerically demonstrate the effects of terrestrial, deep submarine, hot spot and mid ocean ridge volcanism on planktonic and terrestrial life on Earth. What are the errors in your calculations? Rule out water vapor Water vapour is the only important GHG -- Andrew Dodds From the annual average burning of hydrocarbons, lignite, bituminous coal and natural and coal gas, smelting, production of cement, cropping, irrigation and deforestation, use the 25�m, 7�m and 2.5�m wavelengths to calculate the effect that gaseous, liquid and solid H2O have on atmospheric temperature at sea level and at 5 km altitude at latitudes of 20�, 40�, 60� and 80�S. How does the effect of H2O compare with the effect of CO2 derived from the same sources? All assumptions must be justified and calculations and sources of information must be shown. At least one question (#13) is just stupid ? I think he?s just trying to sound impressive. There are numbers of little peaks between 1 and 10 microns for water vapor ? which peaks near 2.5 and 7 microns does he want? Liquid water has peaks at 3 and 6 microns, so ?use the 25�m, 7�m and 2.5�m wavelengths to calculate the effect that gaseous, liquid and solid H2O have on atmospheric temperature? just doesn?t make sense. Ice has a broad band around 2 microns. There?s a CO2 absorption band at 4 microns which doesn?t exist for water vapor, so if you try to examine ?How does the effect of H2O compare with the effect of CO2 derived from the same sources?? you?ll get something completely meaningless. In any event the answer is pretty simple ? all this water vapor will get precipitated out pretty quickly so it won?t have much of an effect.-- Pessce commenting at Greenfyre I laughed very hard at this last one. It?s all a complete mess and meshes together many different problems. There?s absolutely no relation between what we burn for example and the absoprtion properties of water vapor or CO2 (and by the way, for CO2 you want to look near 15 microns and the unsaturated bands on either side). There?s also essentially no effect from water vapor from those sources since it precipitates out quickly and is thus not a climate forcing. This is of course in the gas phase, I?m not sure what information he wants about liquid or solid phases. All togther this is jumbled up nonsense and shows that Plimer is intentionally trying to mislead others. -- Chris Colose, Climate Change So now this waste of electrons (referring to a water vapor trumps C02 claim earlier than Plimer's) is reduced to the claim that the optical depth of the atmosphere is held constant at 1.87 by compensating variations in the water vapor column density in the atmosphere. Well, at least for the Earth's atmosphere right now that is the value, but is it fixed and if it is what is the mechanism? We know that the atmospheric concentration of CO2 is rising which would increase the optical depth. The only way that the optical depth could then decrease is for the water vapor column density to decrease. Measurements show that the surface is warming. Since warmer temperatures will result in higher water vapor pressure, the only way that total water vapor would decrease would be for the excess water to rain out quickly. Although there is some data on water vapor column density from way back when, it is not of the highest quality, and the further back you go, the worse it gets. Is there another way to get at this? Why yes young fella, if you had the right satellite instruments you could look at the water vapor concentration as a function of temperature on the surface over a relatively small area. And guess what we have the right satellite instrument, the Atmospheric Infrared Sounder (AIRS) and Andrew Dessler and friends have used data from this instrument in a paper currently appearing in the Journal of Geophysical Research, and as you would expect if you were not Ferenc Miskolczi, the column density of water vapor increases as the surface temperature below increases. -- Eli Rabett Rabett Run